Background/Rationale: Lung cancer is the leading cause of cancer-related deaths among Veterans and about 7,000 newly cases are diagnosed yearly in VA. Non-small cell lung cancer (NSCLC) is the most common type and accounts for approximately 85% of all lung cancer cases. Majority of new cases are in advanced cancer stages at the initial presentation. The genomic-based for targeted therapy such as erlotinib and crizotinib is emerging as an alternative treatment option for patients diagnosed with lung cancer. Prior to our understanding of NSCLC molecular tumor biology, conventional treatment has generally been standardized, predetermined, non-individualized protocols of systemic platinum-based chemotherapy. Clinical efficacy of erlotinib has demonstrated through randomized clinical trials in patients with NSCLC. Because of lower toxicity profiles in these targeted agents, studies demonstrated that patients with EGFR-positive NSCLC treated with erlotinib had better clinical outcomes and quality of life. However, little is known about values of the delivery of targeted therapy in clinical management for Veterans with advanced NSCLC in routine practice in the VA healthcare system. The goal of the proposed study is to fill these gaps in knowledge. Objectives: Our specific aims are: 1)To examine utilization of the genomic-based targeted therapy in clinical management of Veterans diagnosed with advanced NSCLC within the VA healthcare system; 2) to examine clinical effectiveness of the delivery of targeted therapy in management of Veterans with lung cancer in terms of overall survival within the VA healthcare system; 3) to assess cost and cost-effectiveness of the delivery of targeted therapy in management of Veterans with lung cancer relative to the conventional care within the VA healthcare system; and 4) to examine knowledge, attitude, facilitators and barriers of delivering genomic-based targeted therapy for patients with lung cancer at the VHA. Methods: The proposed project is an observational cohort study using VA clinical and administrative data. Eligible study patients diagnosed with NSCLC will be identified from the VA Central Cancer Registry and followed until death or censored at the end of study. The outcome measures include: overall survival month, adverse events associated with the cancer treatment, treatment cost, and incremental cost per additional life- month gained. The exposure variable is a time-varying measure of the use of erlotinib since patients diagnosed with lung cancer. Patients' demographics, tumor characteristics and comorbidity and facility characteristics will be used as confounding factors when compare clinical effectiveness of erlotinib to the conventional care. Descriptive analyses and multivariate regression models, and qualitative study will be performed to address the stated specific aims. Expected findings of the proposed study will provide us a better understanding about clinical effectiveness and cost-effectiveness of targeted therapy for Veterans with lung cancer, and oncologists' perceptions on use of targeted therapy for lung cancer. Knowledge gained in this study will be used to inform policy decision-maker, clinicians, researchers and lung cancer patients about values of delivering genomic- based targeted therapy for lung cancer treatment in the VA healthcare system.